The lever shifting device for a bicycle, as shown in the Japanese Utility Model Application Gazette No. Sho 57-111,698, comprises an operating lever supported rotatably to a fixing member fixed to a bicycle frame and a positioning mechanism including a positioning member rotatable in association with the operating lever and having a plurality of engaging positions to set the speed change stage of the derailleur and an engaging member supported to the fixing member and engageable with at least one engaging position, thereby ensuring the positioning of the lever at a desired speed change stage.
In order to ensure the positioning condition of the lever, a larger resistance overcoming the return spring of the derailleur must be applied between the positioning member and the engaging member. Hence, the operating lever, when intended to operate against the return spring, should be operated with a larger force than the sum of resistance of the positioning mechanism and the biasing force of the return spring, resulting in poor speed-change efficiency.